This invention relates generally to online systems, and in particular to crediting advertisement impressions on an online system.
Presenting advertisements to users of an online system allows an advertiser to gain public attention for products or services and to persuade online system users to take an action regarding the advertiser's products, services, opinions, or causes. Many online systems generate revenue by displaying advertisements to their users. Frequently, online systems charge advertisers for each presentation of an advertisement to an online system user (e.g., each “impression” of the advertisement).
Additionally, as users more frequently use mobile devices or other devices with limited display area, online systems may combine multiple advertisements into a scrollable advertisement unit. This reduces the display area on which advertisements are presented to reduce the likelihood of user alienation, while allowing users to navigate through the scrollable advertisement unit to view different advertisements. For example, a user may scroll horizontally or vertically through the scrollable advertisement unit to access different advertisements included in the scrollable advertisement unit.
Conventionally, online systems identify an impression of an advertisement if the advertisement is included in a scrollable advertisement, even if a user does not navigate through the scrollable advertisement unit to view the advertisement. For example, a user presented with a scrollable advertisement unit including advertisements does not interact with the scrollable advertisement unit, so only a single one of the advertisements in the scrollable advertisement unit is presented to the user; however, in conventional systems, an impression of each advertisement in the scrollable advertisement unit is credited. Thus, because scrollable advertisement units often present a fewer number of advertisements to a user than the number of advertisements included in the scrollable advertisement unit, conventional systems may identify impressions of advertisements included in a scrollable advertisement that are not displayed to a user. This method of identifying impressions may cause an advertiser to be charged for impressions of advertisements in a scrollable advertisement unit that were not actually displayed to a user.